1020205021553 has 2 divisors, whose sum is σ = 1020205021554. Its totient is φ = 1020205021552.

The previous prime is 1020205021543. The next prime is 1020205021571. The reversal of 1020205021553 is 3551205020201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1019348698384 + 856323169 = 1009628^2 + 29263^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020205021553 - 2²² = 1020200827249 is a prime.

It is not a weakly prime, because it can be changed into another prime (1020205021543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510102510776 + 510102510777.

It is an arithmetic number, because the mean of its divisors is an integer number (510102510777).

Almost surely, 2^{1020205021553} is an apocalyptic number.

It is an amenable number.

1020205021553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020205021553 is an equidigital number, since it uses as much as digits as its factorization.

1020205021553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3000, while the sum is 26.

The spelling of 1020205021553 in words is "one trillion, twenty billion, two hundred five million, twenty-one thousand, five hundred fifty-three".